Getting the lead out of my water carbonator

[saratoga]

A couple years ago I put together a home seltzer/beer system using all stainless steel except for the CO2 regulator. I added a stainless steel double check valve on the CO2 line to try and keep the (acidic) carbonated water vapor from reaching the cheap brass CO2 regulator (which had a Prop 65 warning for lead content on it) and leaching out heavy metals. Initially this worked well, I had the water tested and it lead content came back just above the limited of detection and well below EPA limits for drinking water.

Flash forward a couple years and I got it retested and the lead content in my seltzer has jumped up 8-fold since I built it. I borrowed an XRF and as far as I can tell, literally the only lead in the system is the damn CO2 regulator, which uses 2-3% leaded brass. My theory is that when I change out the CO2 tanks the pressure difference reverses and briefly allows a bit of water through the check valves, which corrodes the brass and leaches out the lead. I've run the tanks empty a few times and left them like that a week or two, so possibly a lot of corrosion has gotten at the brass/lead which is why the lead is going up and up.

At this point I've wasted hundreds of dollars on lead testing and valves to try and salvage $60 regulator when I should have just thrown it in the trash. What are my options for a lead-free Co2 system? I've seen chrome plated brass regulators, but it isn't clear to me if that completely isolates the lead (plus chromium is not great...). I've also seen stainless steel regulators, which seems ideal, but mostly looks like its aimed at industrial/medical applications and no idea what they cost. Are there any good options that aren't thousands of dollars?

 

[doug293cz]

Don't have any recommendations for you, but where does one borrow an XRF?

For those who don't know, an XRF is an X-Ray Fluorescence spectrometer that allows you to do elemental analysis by bombarding the sample with x-rays, and looking at the x-rays that the different atoms emit when they absorb the incident x-rays.

Brew on

 

[marc1]

Sounds like the check valves aren't working?
Maybe double up new ones, with one near the keg and one near the regulator?
Can you disconnect from the keg when changing tanks?
If the current regulator is corroded, maybe replace that as well?
Are you sure it's not your source water that is getting increased lead from somewhere else?

 

[saratoga]

Don't have any recommendations for you, but where does one borrow an XRF?

For those who don't know, an XRF is an X-Ray Fluorescence spectrometer that allows you to do elemental analysis by bombarding the sample with x-rays, and looking at the x-rays that the different atoms emit when they absorb the incident x-rays.

Brew on

It was from the county health department. They were meeting with parent due to lead exposure and I asked about my keg system and they were interested in taking a look. I suppose kegs are important to health

Sounds like the check valves aren't working?
Maybe double up new ones, with one near the keg and one near the regulator?
Can you disconnect from the keg when changing tanks?
If the current regulator is corroded, maybe replace that as well?
Are you sure it's not your source water that is getting increased lead from somewhere else?

I went with the double ball valve with venting device:

https://fs1.cloudsnob.com/static/5a...585793118049__174163__Chudnow_Check_valve.pdf

It is ~3 year old and stainless steel. I'm not sure how these double check valves work, but I wonder if when you flip them from +20 PSI to -65 PSI if a bit of gas does leak backwards during the transition. Otherwise I'm not sure how else lead is going to get into the water. I guess I could buy a second one, but they cost as much as the damn regulator I'm trying to work around.

Source water is lead free (tested input and output of taps) and then goes into a further filtration system - so i'm feeding in very pure water ... which is then filled with heavy metals

I was looking at stainless steel regulators:

https://www.coleparmer.com/i/cole-p...or-1500-scfh-capacity-320-cga-fitting/9820210

CGA320 fittings for ~400. Not outrageous given what I've already spent on valves and water testing. If it does get rid of the lead then it'd be worth it.

 

[saratoga]

Some minor updates:

I checked with coleparmer and they say that all metals used in those regulators are lead-free.

I haven't taken the check-valve apart yet, but I did look at the CO2 pressure and it was about equal to the water pressure. It didn't used to be that way, so perhaps my water PSI changes over time or maybe the regulator valve is drifting. Either way I raised the gas pressure 10 PSI to make sure the gas is always forcing into the carbonator through the valve and never the reverse. One possibility is that if the pressure is higher on the water side of the check valve that it can gradually leak through, or maybe when the toilet flushes and the water pressure oscillates it gets a bit through. I think this shouldn't be possible with the double valve, but who knows.

I'm thinking I'll replace the old lead regulator with the ColeParmer one, test the check valve while I have the system apart, and maybe put in a second check valve in series just to be ultra safe. Probably also soak the carbonator tank in vinegar to get out any scale or heavy metal salts that worked there way in.

 

[saratoga]

After some more research, apparently the Big Mac Carbonators often include lead in the pumps:

https://mmrc.caltech.edu/Procon/ Pump_spec Series1,2,3.pdf

In my testing the outside at least didn't test positive for lead (although I had no way to test the internal parts of the pump...) but the model number indicates this is the 1.5% max lead part. Fortunately the built in check valve should prevent CO2 contact with the lead, but you are depending on the tap water not leaching lead while it sits in the pipe, which isn't great given how long it could sit there in contact.

Interestingly there are stainless steel pumps on some of them:

I guess before I change out the regulator it would be cheaper to swap the pump for stainless steel. Looking at mine it is looking a little tarnished on the outside after years of use. I assume the inside isn't great either.